Refrigeration system for display cabinets, food storage cabinets, and the like



2 Sheets-Sheet l L/u/a mea/v F500i/[RY CONDEMSOR CLOCK COMPRESI A. BORENDISPLAY CABINETS, FOOD STORAGE CABINETS, AND THE `LIKE .lvvenc Hdam5eme/r.

IGERATION SYSTEM FOR Dec. 21. 1965 Filed May 16, 1962' @l r com 4m Jl(ORAGE A. BQREN REFRIGERATION SYSTEM FOR DISPLAY CABINETS. FOOD STCABINETS, AND THE LIKE 2 Sheets--SheefI 2 Filed May 16, 1962 INVENTOR.

Haam Bore/7.

United States 'Patent O 3 224 219 REFRIGERATION SYTEIVI FOR DISPLAYCABI- IEK'IS, FOOD STRAGE CABINETS, AND THE Adam Boren, 300 Deal LakeDrive, Asbury Park, NJ. Filed May 16, 1962, Ser. N0. 195,297 7 Claims.(Cl. (i2-27S) p This invention relates to a novel system ofrefrigeration for display cabinets, food storage cabinets, and the like,remotely located, and with widely different temperature requirements.

In accordance to the present invention a central unit supplies airthrough two lines to the remote cabinets: one supply line being cold, asbelow 20 P.; the other warm, as above |80 F. `The air supplied ininsulated ducts at relatively high velocity and pressure. The air,further, is clean and dehumidied, and reaches each display or storagecabinet at the same two supply temperatures, regardless of the size orrequired temperature condition of the cabinet.

Each refrigeration cabinet contains a novel air mixing anddepressurizing chamber that automatically maintains the localtemperature condition to which it is preset, continuously and ataconstant level. The warm (-|-80 F.) and cold (-20 F.) air supplies aremixed in each individual cabinet in accordance to its intended use andrequired temperature. Such temperature presetting attains a continuousconstant condition; temperature variations being eliminated as nodefrost cycling is needed in the invention cabinets hereof. There thusresults no deterioration of frozen foods, and a minimum of shrinkage ofmeats and produce.

The invention system greatly simplifies installation of multiple typesof display cabinets and storage cabinets, as in a supermarket; as wellas materially reduce its cost. Condensate drains and electricalconnections for local fan motors and defrost heaters are eliminated inthe invention refrigeration cabinets and system. Simple insulatedunderoor ducts for the two system outgoing low and higher temperatureair supply, referred to above, and one for the return (used) air fromthe cabinets, are located in the store region for such cabinets. Thecabinets may be positioned at any point along the supply du-cts,

or simple extensions thereof, regardless of cabinet types or theirrequisite temperatures.

The operating temperature of each cabinet of the invention is adjustableand presettable over a wide range of temperatures. Thus, any suchcabinet may be readily changed as to its operating use and temperaturestate. This permits flexibility of installation, as well assimplification of cabinet manufacture and stocking. An improved usablevolume eiiiciency results in the novel improved cabinets hereof as nocoils or blowers are used therein. Further, there is no restriction asto the .physical size or shape of such cabinets; as the conventionalevaporator cooling coils are not incorporated therein.

The overall refrigeration system hereof is cheaper to manufacture,install, operate and maintain than those of the prior art. The centralunit efiiciently provides the cleaned, dehumidiiied air at both the cold(e.g. less than 20 F.) and warm (eg. above +80 F.) temperatures; andreprocesses the returned (used) air. The central unit forces the airthrough ducts at relatively high pressure and velocity. Economicalinsulated distribution `ducts are used, Vas the refrigerant (c g. Freon)is not transported to the remote cabinets.

Finally, relatively large savings result in the simplified refrigerationcabinets hereof. The air mixing and depressurizing chambers arestandardized. Location of the cabinets in the store, and theirindividual temperaice ture setting, are fully flexible. Ready change ofproduct usage, temperature and cabinet arrangement is feasible with myinvention system.

The above and other features, advantages and objects of the presentinvention will become more apparent from the following description of anexemplary embodiment thereof, illustrated in the drawings, in which:

FIG. 1 is a diagram of the invention refrigeration system. p

FIG. 2 is an enlarged diagrammatic showing of the exemplary centralrefrigeration air supply unit of the invention.

FIG. 3 is a cross-sectional View through a display cabinet hereof.

Referring to FIG. l, the central refrigeration air supply unit 15provides air at low temperature (eg. below -20 F.), through output duct16; and air at higher temperature (eg. above E), through duct 17. Theair is supplied cleaned and dehumiditied, and under a relatively highpressure and velocity that is optional for particular systems. The lowand high temperature air under pressure is supplied to and through thecabinet areas in the .market by distribution ducts 20 and 21. Thesedistribution ducts are economically made of fiber glass, cork,Styrofoam, etc.

The airducts 20, 21 are connected to the individual display cabinetsand/ or storage cabinets 25 through respective branch ducts. The returnor used air from the cabinets 25 is returned to central unit 15 throughbranch ducts 26 feeding into return distribution duct 27. Duct 27couples to the return input duct 28 of unit 15. The distribution ducts20, 21 and 27 are directed in any desired paths, as will be understoodby those skilled in the art. The three branch ducts 22, 23 and 26 foreach cabinet are suitably coupled to the distribution ducts byrespective tape 30, 31 and 32.

General operation of system The air returning vfrom the cabinets 25through return distribution ducts 27 feeds into secondary blower fanchamber 35. The returned air is thereupon propelled along connectingducts 36, 37, 38 to one (40) of two alternateddehumidifying-precooling-purifying chambers 40, 40'. The .precooled dryair is conducted thru duct 41 into primary blower fan chamber 42. It isforced under high pressure and velocity through an evaporator coolingcoil unit 43; and a portion independently through a heating coil unit44.

The high pressure cold air at output duct 16 is at below 20 F. in theexemplary system; the warm air at line 17, at above |80u F. Differentinstallation requirements may indicate somewhat different temperaturevalues. The air supply is therefore at relatively highpressure and flowsat relatively high velocity through the distribution ducts 20, 21 to thevarious utilization cabinets 25. The air from the cabinets 25 returnsthrough ducts 27 to complete the circuit. Details of the operation andcomponents of central unit 15 will be set forth hereinafter inconnection with FIG. 2.

While one of the two dehumidifying-precooling-purifying chambers 40, 40'is in basic operation, as described hereinabove, the other one is beingdefrosted. Thus the `chamber unit 40 in FIG. 1 is shown in its defrostphase,

while unit 40 is in normal operation. A time clock control 45 is used topredeterminedly cycle the operationdefrost phasing of the units 40, 40',`as detailed hereinafter. Suitable motorized dampers (see FIG. 2) areused to redirect the air from chamber 35 into unit 40 or 40', and fromthe output of units 40' or 40' into chamber 42.

A defrost chamber 46 connects to an outside-air intake duct 47, andcontains a blower section 48 and heater section 49. In the phase shownin FIG. 1, the defrost heated-air from chamber 46 is directed throughits output duct 50 and duct 51 into unit 40. During this cycle, heatedair from chamber 46 defrosts accummulations of frost on the evaporatorcoils in unit 40', and exits through duct 91 to the outside air. Whenunit 40 is switched into the defrost cycle connection with chamber 46,the defrosted alternate unit 40' replaces unit 40 between secondaryblower fan chamber 35 and primary blower fan chamber 42. This recyclingor alternation of units 40 and 40 between their operational and defrostphases is initiated by the clock control 45, on a preset automaticbasis; as for 30 or 60 minutes, or other interval.

The evaporator coil cooling sections in units 40, 40' and 43 are ofconventional construction. A refrigerant gas, as Freon, as passedthrough these coils. A compressor 55 compresses the Freon gas from thereturn section line 54, in its cylinder 56. The compressed hot (Freon)gas Hows into output line 57 of compressor 55 in a conventional manner.The hot gas output 57 of compressor 55 is by-passed en route to thecondenser 58 in order to extract and utilize a substantial portion ofits contained heat in central unit 15. Such heat utilization reduces thepower requirement of the system 15, thereby improving its overalleciency. The somewhat cooled compressed Freon returns from unit 15 toinput line 59 of condenser 58; and thereupon enters a liquid Freonreceiver 60 through line 61 The liquid refrigerant (Freon) line 64supplies the refrigerant to the several evaporator coolings coils of thesystem 15, as at 40, 40', 44. Liquid line 64 is fed from receiver 60through preset valve 62 and connection line 63. The indicatedcompressor, condenser and receiver are of conventional construction andin the exemplary embodiment use Freon as the refrigerant. While the heatutilization by-pass to unit 15 between outside lines 57 and 59 isdesirable, it is to be understood that the heating requirement atchambers 44 and 49 'may be otherwise supplied. Thus electrical resistiveheating may be used to supplement or supplant that of such bypass.

The evaporator cooling coils of chamber unit 42 and of thedehumidifying-precooling-purifying units 40, 40' are supplied inparallel from the liquid (Freon) line 64. The coil 43 is fed by aconnecting line 65 through a local expansion valve 66, with the line 67for return to the suction line 54. The evaporator soil set of unit 4l)is supplied by line 70 through a local expansion valve 71, and a returnline 72; and that of unit 40 through line 73, local expansion valve 74,and return line 75.

The evaporator cooling coil 43 of chamber 42 operates on air that isdry, and therefore does not frost up. Coil 43 is directly connectedacross lines 54, 64 continuously. The units 40 and 40' are regularlycycled or alternated in their system operation; being defrosted when outof circuit. Towards this end electrically operated solenoid valves 76and 76 are respectively inserted in lines 70 and 73 to the evaporatorcoils in units 40 and 40'. Valve 76 is normally open; valve 76',normally closed. These are alternately cycled, electrically, by controlclock 45, admitting liquid Freon to unit 40 or 40' only while it is inits operating phase; and shutting off such flow when in its defrostphase.

The heating by-pass arrangement for heating coil 44 in unit 42 and coil49 in unit 46 is in series connection between compressed hot gas lines57 and S9. These are connected by line 77 from line 57 to coil 49; line78 between coils 49 and 44; and to line 59 of condenser 58 throughconnecting line 79. As stated hereinabove, other conventional means forheating at the chamber sections 44 and 49 may be used. The chambersections of unit 42 containing evaporator cooling coil 43 and heatingcoil 44 are thermally insulated from each other.

Operation of central unit 15 FIG. 2 illustrates the central unit 15 inenlarged schematic form, in the phase wherein unit 40 is in operation,and alternate unit 40 in defrost The evaporator cooling coil and heatingcoil circuits (FIG. 1), are omitted for clarity of presentation. Thereturn air from the cabinets 25 enters central unit 15 through inputduct 28 at chamber 35. The air passes a set of iilters 81 to trap itsdust particles. A secondary blower fan propels the air into unit 40 or40 in accordance with the phase setting of the ducts and motorizeddampers for this purpose, as will now be described.

In the illustrated phase, the air from chamber 35 is directed from exitduct 36 through duct 37 past normally open damper 82 to line 38 intounit 40. Adjacent dampers 83 and 84 are normally closed; and damper 85,normally open. Dampers 82-85 are motor operated through control motor 86and geared shafting 87, 88, 89 indicated by dashed lines. Alternativelyeach damper may be controlled by an individual motor. In this phase,also, duct 90 at cooling end of unit 40 is made to communicate directlyto exhaust duct 91 through normally open damper 85; damper 84 being shutat such period.

The filtered warm return air from chamber 35 is thereupon propelled intounit 40 for dehumidifying, precooling and purifying. It passes firstthrough a wider-spaced multi-row iin evaporator coil 92 which serves asa primary air dehumidifier and precooler. The air then passes through acloser-spaced multi-row iin evaporator coil 93, at a substantially lowertemperature than coil 92, which serves as a secondary dehumidifier andprecooler. The next stage in unit 40 is a bank 94 of conventionalchemical dehumidiiiers for the cooled air passing through, followed byan electrostatic filter 95 which optionally may contain an ozonegenerator.

The air thus emerges from unit 40 substantially precooled, e.g. to 0 F.;relatively moisture free, clean, and odor free. In an identical manner,air when projected into unit 40 through duet 90, in the alternatecycles, is precooled, cleaned and dehumidified through components 92',93', 94 and 95. In the illustrated phase, the precooled air from unit 40passes into duct 39, through normally open damper 96, and on throughduct 41 into primary chamber 42. Dampers 97, 98 are normally closed inthis phase, while damper 99 is normally open.

The dampers 96-99 are operated cyclically by control motor 100. They arecoupled to motor 100 by suitable geared shafting as indicated, and aswill now be understood. Control motors 86 and 100 are operatedcyclically by clock controller 45 through electric cables schematicallyindicated at 101, as are solenoid valves 76, 76 (see FIG. 1). Further,instead of two central motors 86, 100, an individual motor may be usedat each damper. The successive alternate cycling effects the defrostmode for unit 40, and the operation mode for unit 40. The alternatecycle is accomplished by reversal of all the damper settings from thoseillustrated. Those dampers (82, 85, 96, 99) shown normally open in FIG.2 are closed; and those dampers (83, 84, 97, 98) normally closed, areopenedf The basic clock controller 45 is suitably connected to operateunits 40 and 40 in the alternate modes described hereinabove, throughcontrol motors 86,100 and solenoid valves 76, 76', as will be understoodby those skilled in the art. When the precooled, cleaned and dehumidiedreturn air from unit 40 (or 40') enters duct 41, it passes into chamber42. There the primary blower fan propels this cooled dry air in partthrough cooling coil seotion 43, and in part through heating coilsection 44. Blower fan 105 impels the air at high pressure and thus highvelocity.

The evaporator cooling coil 43 is closely-spaced and of multi-finconstruction. The enclosures 43 and 44 are suitably separated andinsulated from each other. The

.5 supply 4output duct 16 of primary cooling section 43 feedsdistribution duct 20. The supply duct 17 of heating section 44 feedsdistribution duct 21. The heating coil at section 44 is fed yby the hotgas (Freon) line 78 (see FIG. 1), couples to line 59; and is in serieswith heater coil 49, as already described.

The alternated defrosting cycles for units 40 and 40' are preset andeffected through the master clock controller 45, damper control motors86,100, and electrical solenoid valves 76. 76', in the mannerhereinabove set forth. In FIG. 2 unit 40 4is shown connected in thedefrost phase. The defrost system chamber 46 contains a blower fan 110which sucks in outside air through intake duct 47 that is cleansed -byair lter 111. The heating coil 49 raises the air temperature, whichthereupon is propelledthrough duct 50' to opened damper 99 and on tounit 40 through duct 51. A defrost air temperature into unit 40' of over80 F. is desirable.

The defrost hot-air in turn dehydrates the chemical dehumidifiercomponent 94', and defrosts icy accumulations on the evaporator coils 93and 92. The now moistureladen air in unit 40 exits through opened damper85 and exhaust duct 91 to the outside air. A defrost cycle of 30, 60 ormore minutes is commercially suicient in the exemplary system. Duringthe defrosting of unit 40 alternate unit 40 has been preconditioning thesupply air for primary chamber 42, but accumulating moisture and froston its coils (92, 93) in the process, Cycle change through clockcontroller 45 is rapidly accomplished. When unit 40 is put into defrostunit 40' thereupon resumes preconditioning air for primary chamber 42.The air supplied to distribution ducts 20, 21 and the cabinets 25 thusremains effectively continuous.

Operation of refrigeration cabinets A typical display cabinet 25 of thisinvention is seen in plan view in FIG. 1, with its automaticallyfunctioning but preset chamber 115 shown schematically; and in verticalcross-sectional view in FIG. 3. The exemplary air mixing anddepressurizing chamber 115 is disposed in a flat space along the bottomof the cabinet 25. It contains no motors, fans, evaporator cooling coilsetc., and is therefor compact, economical, and flexible of orientationin any desired cabinet size, shape of end use.

Each cabinet is individually presettable over a wide range of operatingtemperatures, dependent upon its usage; and maintains its presettemperature constantly and constant. There is no shut-down period fordefrosting coils in the cabinet as in prior art constructions. Hencethere is no deterioration of foods stored. Typical display and/orstorage cabinet (25) t preset temperatures, all directly afforded by myinvention, are:

F. (a) For ice cream -20 (b) For frozen foods -5 (c) For frozen meatsand fish 0 (d) For fresh meat +32 to 36 (e) For dairy products 36 to 40(f) For produce 40 to 45 The air mixing and depressurizing chamber 115has two inlet air openings namely opening 116 for cold supply air; andopening 117 for the warm supply air. Cold air is supplied by inlet duct22; and warm air, by inlet duct 23; both being tapped at 30 and 31respectively to the distribution ducts 20, 21. The exemplary system usescold air supply at below 20 F. and warm air supply at above +80 F., asaforesaid; and other temperature values may be instead used wheredesired.

A thermostatically controlled damper 118 in the Warm air supply inlet117 controls the amount of warm air entering for the required airtemperature mixing for the cabinet 25. A pressure controlled damper 120determines the amount of total mixed air (hot and warm), and itspressure, to exit from the air mixing enclosure 122. The rate of warmair entry is regulated by the degree of opening of pivoted damper 118,directly controlled by rod 119, through bi-metallic temperaturesensitive thermostat 124. Thermostat 124 is located in the region 125 ofthe emerg. ing mixed air at the cabinet temperature; and when manuallypreset serves to maintain the air output mixture at a constanttemperature level.

The air depressurizing damper comprises a bowlshaped element 126suspended near the air inlets 116, 117 by rod 127. A pressurestat 128controls the damper bowl 126 location with respect to the inlets 116,117, to elect the predetermined resultant mixed air proportion andvolume output and mixture temperature. Pressurestat 128 is sping-loaded,pressure sensitive, and presettable manually. The air mixing anddepressurizing chamber 120 is thus held at the desired pressure andmixing temperature.

The mixed air exits from region into the plenum chamber 130 along the.back of the display cabinet 25. The air then exits through directionalair Ioutlet louvres 131 over the product 135 in the cabinet, in thedirection indicated by arrows 132. The directed air thereupon entersreturn louvres 133 into the return air plenum chamber 135 along thefront of the cabinet 25. The amount of return air is controlled by amanually preset damper 136 located in the air exit Iof the return airplenum chamber 134. The air then returns to the distribution duct 27through its branch duct 26.

Although the present invention has been set forth in connection with anexemplary embodiment, it is to be understood that modifications may bemade there-in as to its arrangement, application and temperature rangesthat fall Within the broader spirit and scope of my invention as setforth in the appended claims.

I claim:

1. In combination with a closed cycle refrigeration system forrefrigeration units such as display cabinets and foo-d storage cabinetswhich have means for mixing hot and cold air supplied to hot and coldinlets thereof and a return outlet for the mixed air comprising acentral unit with separate heating and cooling sections for air suppliedto an inlet of the central unit, said central unit having hot and coldair -outlets connected to and downstream of said heating and coolingsections, respectively, means for connecting said hot and cold airoutlets of said central unit with the hot and cold air inlets of thestorage cabinets, respectively, dehumidifying and cooling means havingan inlet and outlet, means for supplying mixed air deriving from saidoutlet of the refrigeration unit to the inlet of said dehumidifying andcooling unit, and means coupling the outlet of said dehumidifying andcooling means as the only air supplied to the inlet of said centralunit, said air supplied to said central unit from said dehumidifying andcooling means thereby being supplied to the heating and cooling sectionsof said central unit.

2. The system of claim 1 further including means for cleaning the airderiving from said refrigeration equipment prior to the said air beingapplied to the inlet orifice 4of said -central unit, said cleaning meansbeing disposed in the path between the outlet of said refrigeration unitand the inlet of said central unit.

3. In combination with a closed cycle refrigeration system comprising acentral unit with heating and cooling sections for air supplied thereto,said unit having hot and cold air outlets connected to and downstream ofsaid heating and cooling sections, respectively, a refrigeration unithaving a hot air inlet and a cold air inlet and means for mixing the hotand cold air supplied to its inlets, means for connecting the hot airoutlet of said central unit with -the hot air inlet of saidrefrigeration unit, means for connecting the cold air outlet of saidcentral unit with said cold air inlet of said refrigeration unit, saidrefrigeration unit having an outlet for withdrawing the mixed air,dehumidifying and cooling means connected downstream from the outlet ofsaid yrefrigeration unit to dehumidify and cool only the mixed airderiving from said refrigeration unit, and means for connecting theoutlet of said dehumidifying and cooling means -as the only air inlet tsaid central unit so that the only air that is heated and cooled in saidcentral unit is derived from said dehumidifying and cooling unit.

4. The refrigeration system of claim 3 wherein said dehumidifying andcooling means includes -a pair of dehumidfifying and cooling units,means for selectively connecting only one of said dehumidifying andcooling units between the outlet of said refrigeration unit and theinlet of said central unit, and means for defrosting the other of saiddehumidifying and cooling units while the iirst named dehumidifying andcooling unit is connected between said refrigeration unit outlet andsaid central unit inlet.

5. The refrigeration system of claim 3 wherein said heating section ofsaid central unit includes a rst heat exchange coil and the coolingsection of said central unit includes a second heat exchange coil, meansfor circulating a refrigerant in a closed loop through both of said heatexchange coils, said last named means including a compressor having itsinlet connected downstream of said second heat exchange coil to beresponsive to the heated refrigerant deriving from said second heatexchange coil, said compressor having an outlet connected upstream ofsaid rst heat exchange coil for supplying heated refrigerant to said rstcoil, means for condensing and recovering refrigerant connecteddownstream from said rst coil and having an outlet connected upstream ofthe inlet for said second coil for supplying cooled refrigerant to saidsecond coil.

6. The refrigeration system of claim 5 wherein said dehumidifying andcooling means includes a pair of dehumidifying and cooling units betweenthe outlet of said refrigeration and the inlet of said central unit,means for defrosting the other of said dehumidifying and cooling unitswhile `the first named dehumidifying and cooling unit is connectedbetween said refrigeration unit outlet and said central unit inlet, andmeans connected in parallel with said second heat exchange coil forsupplying the cooled refrigerant to only the dehumidifying and coolingunit connected with the inlet of said central unit.

7. The refrigeration system of claim 6 wherein said defrosting meansinclude means for supplying heated air to the dehumidifying and coolingunit being defrosted, said last named means including another heatexchange coil connected in said closed loop between said compressor andsaid first heat exchange coil, said another heat exchange coil heatingthe air supplied to said dehumidifying and cooling unit being defrosted.

References Cited by the Examiner UNITED STATES PATENTS 2,343,467 3/1944McGrath 165-17 2,609,743 9/1952 Ashley 165-22 X 2,755,072 7/1956Kreuttner 165-22 X 2,811,223 10/1957 Newton 62-271 X 2,815,915 12/1957Salerno 236-13 2,821,343 6/1958 Payne 236-13 2,850,242 9/1958 Newton236-13 2,867,988 1/1959 Brandt 62-275 X 2,880,752 4/1959 Kreuttner.

2,946,201 7/1960 Munters 62-271 X 2,969,959 1/1961 Kuhn et al. 165-17OTHER REFERENCES IBM Technical Disclosure Bulletin vol. 1, No. 4, p. 25,December 1958.

CHARLES SUKALO, Primary Examiner.

1. IN COMBINATION WITH A CLOSED CYCLE REFRIGERATION SYSTEM FORREFRIGERATION UNIT SUCH AS DISPLAY CABINETS AND FOOD STORAGE CABINETSWHICH HAVE MEANS FOR MIXING HOT AND COLD AIR SUPPLIED TO HOT AND COLDINLETS THEREOF AND A RETURN OUTLET FOR THE MIXED AIR COMPRISING ACENTRAL UNIT WITH SEPARATE HEATING AND COOLING SECTIONS FOR AIR SUPPLIEDTO AN INLET OF THE CENTRAL UNIT, SAID CENTRAL UNIT HAVING HOT AND COLDAIR OUTLETS CONNECTED TO AND DOWNSTREAM OF SAID HEATING AND COOLINGSECTIONS, RESPECTIVELY, MEANS FOR CONNECTING SAID HOT AND COLD AIROUTLETS OF SAID CENTRAL UNIT WITH THE HOT AND COLD AIR INLETS OF THESTORAGE CABINETS, RESPECTIVELY, DEHUMIDIFYING AND COOLING MEANS HAVINGAN INLET AND OUTLET, MEANS FOR SUPPLYING MIXED AIR DERIVING FROM SAIDOUTLET OF THE REFRIGERATION UNIT TO THE INLET OF SAID DEHUMIDIFYING ANDCOOLING UNIT, AND MEANS COUPLING